﻿using System;
using System.Collections.Generic;
using System.DrawingCore;
using System.DrawingCore.Drawing2D;
using System.DrawingCore.Imaging;
using System.IO;
using System.Text;

namespace OpenMms.Common.CodeHelp
{
        public sealed class VerifyCodeHelper
        {
            #region 单例模式  
            //创建私有化静态obj锁    
            private static readonly object _ObjLock = new object();
            //创建私有静态字段，接收类的实例化对象    
            private static VerifyCodeHelper _VerifyCodeHelper = null;
            //构造函数私有化    
            private VerifyCodeHelper() { }
            //创建单利对象资源并返回    
            public static VerifyCodeHelper GetSingleObj()
            {
                if (_VerifyCodeHelper == null)
                {
                    lock (_ObjLock)
                    {
                        if (_VerifyCodeHelper == null)
                            _VerifyCodeHelper = new VerifyCodeHelper();
                    }
                }
                return _VerifyCodeHelper;
            }
            #endregion

            #region 生产验证码  
            public enum VerifyCodeType { NumberVerifyCode, AbcVerifyCode, MixVerifyCode };

            /// <summary>  
            /// 1.数字验证码  
            /// </summary>  
            /// <param name="length"></param>  
            /// <returns></returns>  
            private string CreateNumberVerifyCode(int length)
            {
                int[] randMembers = new int[length];
                int[] validateNums = new int[length];
                string validateNumberStr = "";
                //生成起始序列值    
                int seekSeek = unchecked((int)DateTime.Now.Ticks);
                Random seekRand = new Random(seekSeek);
                int beginSeek = seekRand.Next(0, Int32.MaxValue - length * 10000);
                int[] seeks = new int[length];
                for (int i = 0; i < length; i++)
                {
                    beginSeek += 10000;
                    seeks[i] = beginSeek;
                }
                //生成随机数字    
                for (int i = 0; i < length; i++)
                {
                    Random rand = new Random(seeks[i]);
                    int pownum = 1 * (int)Math.Pow(10, length);
                    randMembers[i] = rand.Next(pownum, Int32.MaxValue);
                }
                //抽取随机数字    
                for (int i = 0; i < length; i++)
                {
                    string numStr = randMembers[i].ToString();
                    int numLength = numStr.Length;
                    Random rand = new Random();
                    int numPosition = rand.Next(0, numLength - 1);
                    validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
                }
                //生成验证码    
                for (int i = 0; i < length; i++)
                {
                    validateNumberStr += validateNums[i].ToString();
                }
                return validateNumberStr;
            }

            /// <summary>  
            /// 2.字母验证码  
            /// </summary>  
            /// <param name="length">字符长度</param>  
            /// <returns>验证码字符</returns>  
            private string CreateAbcVerifyCode(int length)
            {
                char[] verification = new char[length];
                char[] dictionary = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
                'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
            };
                Random random = new Random();
                for (int i = 0; i < length; i++)
                {
                    verification[i] = dictionary[random.Next(dictionary.Length - 1)];
                }
                return new string(verification);
            }

            /// <summary>  
            /// 3.混合验证码  
            /// </summary>  
            /// <param name="length">字符长度</param>  
            /// <returns>验证码字符</returns>  
            private string CreateMixVerifyCode(int length)
            {
                char[] verification = new char[length];
                char[] dictionary = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
                '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
            };
                Random random = new Random();
                for (int i = 0; i < length; i++)
                {
                    verification[i] = dictionary[random.Next(dictionary.Length - 1)];
                }
                return new string(verification);
            }

            /// <summary>  
            /// 产生验证码（随机产生4-6位）  
            /// </summary>  
            /// <param name="type">验证码类型：数字，字符，符合</param>  
            /// <returns></returns>  
            public string CreateVerifyCode(VerifyCodeType type)
            {
                string verifyCode = string.Empty;
                Random random = new Random();
                int length = 4;// random.Next(4, 6);
                switch (type)
                {
                    case VerifyCodeType.NumberVerifyCode:
                        verifyCode = GetSingleObj().CreateNumberVerifyCode(length);
                        break;
                    case VerifyCodeType.AbcVerifyCode:
                        verifyCode = GetSingleObj().CreateAbcVerifyCode(length);
                        break;
                    case VerifyCodeType.MixVerifyCode:
                        verifyCode = GetSingleObj().CreateMixVerifyCode(length);
                        break;
                }
                return verifyCode;
            }
            #endregion

            #region 验证码图片  
            /// <summary>  
            /// 验证码图片 => Bitmap  
            /// </summary>  
            /// <param name="verifyCode">验证码</param>  
            /// <param name="width">宽</param>  
            /// <param name="height">高</param>  
            /// <returns>Bitmap</returns>  
            public Bitmap CreateBitmapByImgVerifyCode(string verifyCode, int width, int height)
            {
                Font font = new Font("Arial", 14, (FontStyle.Bold | FontStyle.Italic));
                Brush brush;
                Bitmap bitmap = new Bitmap(width, height);
                Graphics g = Graphics.FromImage(bitmap);
                SizeF totalSizeF = g.MeasureString(verifyCode, font);
                SizeF curCharSizeF;
                PointF startPointF = new PointF(0, (height - totalSizeF.Height) / 2);
                Random random = new Random(); //随机数产生器  
                g.Clear(Color.White); //清空图片背景色    
                for (int i = 0; i < verifyCode.Length; i++)
                {
                    brush = new LinearGradientBrush(new Point(0, 0), new Point(1, 1), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)));
                    g.DrawString(verifyCode[i].ToString(), font, brush, startPointF);
                    curCharSizeF = g.MeasureString(verifyCode[i].ToString(), font);
                    startPointF.X += curCharSizeF.Width;
                }

                //画图片的干扰线    
                for (int i = 0; i < 10; i++)
                {
                    int x1 = random.Next(bitmap.Width);
                    int x2 = random.Next(bitmap.Width);
                    int y1 = random.Next(bitmap.Height);
                    int y2 = random.Next(bitmap.Height);
                    g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                }

                //画图片的前景干扰点    
                for (int i = 0; i < 100; i++)
                {
                    int x = random.Next(bitmap.Width);
                    int y = random.Next(bitmap.Height);
                    bitmap.SetPixel(x, y, Color.FromArgb(random.Next()));
                }

                g.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap.Width - 1, bitmap.Height - 1); //画图片的边框线    
                g.Dispose();
                return bitmap;
            }

            /// <summary>  
            /// 验证码图片 => byte[]  
            /// </summary>  
            /// <param name="verifyCode">验证码</param>  
            /// <param name="width">宽</param>  
            /// <param name="height">高</param>  
            /// <returns>byte[]</returns>  
            public byte[] CreateByteByImgVerifyCode(string verifyCode, int width, int height)
            {
                Font font = new Font("Arial", 14, (FontStyle.Bold | FontStyle.Italic));
                Brush brush;
                Bitmap bitmap = new Bitmap(width, height);
                Graphics g = Graphics.FromImage(bitmap);
                SizeF totalSizeF = g.MeasureString(verifyCode, font);
                SizeF curCharSizeF;
                PointF startPointF = new PointF(0, (height - totalSizeF.Height) / 2);
                Random random = new Random(); //随机数产生器  
                g.Clear(Color.White); //清空图片背景色    
                for (int i = 0; i < verifyCode.Length; i++)
                {
                    brush = new LinearGradientBrush(new Point(0, 0), new Point(1, 1), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)), Color.FromArgb(random.Next(255), random.Next(255), random.Next(255)));
                    g.DrawString(verifyCode[i].ToString(), font, brush, startPointF);
                    curCharSizeF = g.MeasureString(verifyCode[i].ToString(), font);
                    startPointF.X += curCharSizeF.Width;
                }

                //画图片的干扰线    
                for (int i = 0; i < 10; i++)
                {
                    int x1 = random.Next(bitmap.Width);
                    int x2 = random.Next(bitmap.Width);
                    int y1 = random.Next(bitmap.Height);
                    int y2 = random.Next(bitmap.Height);
                    g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                }

                //画图片的前景干扰点    
                for (int i = 0; i < 100; i++)
                {
                    int x = random.Next(bitmap.Width);
                    int y = random.Next(bitmap.Height);
                    bitmap.SetPixel(x, y, Color.FromArgb(random.Next()));
                }

                g.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap.Width - 1, bitmap.Height - 1); //画图片的边框线    
                g.Dispose();

                //保存图片数据    
                MemoryStream stream = new MemoryStream();
                bitmap.Save(stream, ImageFormat.Jpeg);
                //输出图片流    
                return stream.ToArray();

            }
            #endregion
        }
    }